The stock KI arrows do very well with a comparatively low foc. Just like a 2219 out of a traditional railed crossbow with a low foc, yet still shoots great. I think that very stiff shafts in crossbows require less foc. The barrel keeps an arrow almost perfectly straight making it act like an extremely stiff shaft.
SWATs can get by with fairly low foc’d arrows.
But, we can’t get around the fact that the more the point pulls the arrow thru the air, the more accurate it generally is. Just try the factory arrows, as accurate as they are with 100g points, with 170/175g points observe that the groups tighten even more.